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  <li><a href="#基本数据类型" id="toc-基本数据类型" class="nav-link active" data-scroll-target="#基本数据类型"><span class="header-section-number">4.1</span> 基本数据类型</a></li>
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  <li><a href="#数学运算" id="toc-数学运算" class="nav-link" data-scroll-target="#数学运算"><span class="header-section-number">4.4.1</span> 数学运算</a></li>
  <li><a href="#比较运算" id="toc-比较运算" class="nav-link" data-scroll-target="#比较运算"><span class="header-section-number">4.4.2</span> 比较运算</a></li>
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<h1 class="title"><span class="chapter-number">4</span>&nbsp; <span class="chapter-title">基本数据类型</span></h1>
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<section id="基本数据类型" class="level2" data-number="4.1">
<h2 data-number="4.1" class="anchored" data-anchor-id="基本数据类型"><span class="header-section-number">4.1</span> 基本数据类型</h2>
<p>数值型</p>
<div class="cell">
<div class="sourceCode cell-code" id="cb1"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a>a <span class="ot">=</span> <span class="dv">1</span>   </span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
</div>
<p>字符型，双引号括起来</p>
<div class="cell">
<div class="sourceCode cell-code" id="cb2"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a>b <span class="ot">=</span> <span class="st">"hi"</span> </span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
</div>
<p>逻辑型，TRUE和FALSE，可以缩写成T或者F</p>
<div class="cell">
<div class="sourceCode cell-code" id="cb3"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a>c <span class="ot">=</span> <span class="cn">TRUE</span> </span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
</div>
</section>
<section id="查看类型" class="level2" data-number="4.2">
<h2 data-number="4.2" class="anchored" data-anchor-id="查看类型"><span class="header-section-number">4.2</span> 查看类型</h2>
<div class="cell">
<div class="sourceCode cell-code" id="cb4"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb4-1"><a href="#cb4-1" aria-hidden="true" tabindex="-1"></a><span class="fu">class</span>(a)</span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] "numeric"</code></pre>
</div>
<div class="sourceCode cell-code" id="cb6"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a><span class="fu">class</span>(b)</span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] "character"</code></pre>
</div>
<div class="sourceCode cell-code" id="cb8"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="fu">class</span>(c)</span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] "logical"</code></pre>
</div>
</div>
</section>
<section id="判断类型与转换类型" class="level2" data-number="4.3">
<h2 data-number="4.3" class="anchored" data-anchor-id="判断类型与转换类型"><span class="header-section-number">4.3</span> 判断类型与转换类型</h2>
<div class="cell">
<div class="sourceCode cell-code" id="cb10"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="fu">is.numeric</span>(<span class="st">"1"</span>)</span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] FALSE</code></pre>
</div>
<div class="sourceCode cell-code" id="cb12"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="fu">as.numeric</span>(<span class="st">"1"</span>)</span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] 1</code></pre>
</div>
</div>
</section>
<section id="基本运算符" class="level2" data-number="4.4">
<h2 data-number="4.4" class="anchored" data-anchor-id="基本运算符"><span class="header-section-number">4.4</span> 基本运算符</h2>
<section id="数学运算" class="level3" data-number="4.4.1">
<h3 data-number="4.4.1" class="anchored" data-anchor-id="数学运算"><span class="header-section-number">4.4.1</span> 数学运算</h3>
<p>“+ - * / ^”</p>
<div class="cell">
<div class="sourceCode cell-code" id="cb14"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb14-1"><a href="#cb14-1" aria-hidden="true" tabindex="-1"></a><span class="dv">1</span> <span class="sc">+</span> <span class="dv">2</span></span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] 3</code></pre>
</div>
<div class="sourceCode cell-code" id="cb16"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="dv">1</span> <span class="sc">+</span> <span class="st">"1"</span></span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-error">
<pre><code>Error in 1 + "1": 二进列运算符中有非数值参数</code></pre>
</div>
<div class="sourceCode cell-code" id="cb18"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="dv">2</span> <span class="sc">+</span> <span class="cn">TRUE</span></span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] 3</code></pre>
</div>
<div class="sourceCode cell-code" id="cb20"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="dv">2</span> <span class="sc">+</span> <span class="cn">FALSE</span></span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] 2</code></pre>
</div>
<div class="sourceCode cell-code" id="cb22"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="dv">2</span> <span class="sc">+</span> <span class="st">"TRUE"</span></span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-error">
<pre><code>Error in 2 + "TRUE": 二进列运算符中有非数值参数</code></pre>
</div>
</div>
<p>数值型和字符型之间做运算会报错</p>
</section>
<section id="比较运算" class="level3" data-number="4.4.2">
<h3 data-number="4.4.2" class="anchored" data-anchor-id="比较运算"><span class="header-section-number">4.4.2</span> 比较运算</h3>
<p>“&gt; &lt; &gt;= &lt;= == !=”</p>
<div class="cell">
<div class="sourceCode cell-code" id="cb24"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="dv">1</span> <span class="sc">&gt;</span> <span class="dv">2</span></span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] FALSE</code></pre>
</div>
<div class="sourceCode cell-code" id="cb26"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="dv">1</span> <span class="sc">==</span> <span class="dv">2</span></span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] FALSE</code></pre>
</div>
</div>
</section>
<section id="逻辑运算符" class="level3" data-number="4.4.3">
<h3 data-number="4.4.3" class="anchored" data-anchor-id="逻辑运算符"><span class="header-section-number">4.4.3</span> 逻辑运算符</h3>
<p>&amp; |</p>
<div class="cell">
<div class="sourceCode cell-code" id="cb28"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a>T <span class="sc">&amp;</span> F</span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] FALSE</code></pre>
</div>
<div class="sourceCode cell-code" id="cb30"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a>T <span class="sc">|</span> F</span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] TRUE</code></pre>
</div>
</div>
<p>只有当<code>&amp;</code>符号两边同时为True时才会返回T</p>
<p>只有当<code>|</code>符号两边同时为False时才会返回F</p>
</section>
<section id="小结" class="level3" data-number="4.4.4">
<h3 data-number="4.4.4" class="anchored" data-anchor-id="小结"><span class="header-section-number">4.4.4</span> 小结</h3>
<p>数学运算法返回的是结果是数值型；比较和逻辑运算返回的是结果是逻辑型</p>
</section>
</section>
<section id="缺失值" class="level2" data-number="4.5">
<h2 data-number="4.5" class="anchored" data-anchor-id="缺失值"><span class="header-section-number">4.5</span> 缺失值</h2>
<ul>
<li><p>NA 缺失值</p></li>
<li><p>NaN 非数</p></li>
<li><p>NULL 空</p></li>
<li><p>Inf 无穷大</p></li>
<li><p>NA具有传染性，NA参与的运算，就够会变成NA</p></li>
</ul>
<div class="cell">
<div class="sourceCode cell-code" id="cb32"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="dv">1</span> <span class="sc">+</span> <span class="cn">NA</span></span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] NA</code></pre>
</div>
<div class="sourceCode cell-code" id="cb34"><pre class="sourceCode r code-with-copy"><code class="sourceCode r"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="fu">is.na</span>(<span class="cn">NA</span>)</span></code><button title="复制到剪贴板" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>[1] TRUE</code></pre>
</div>
</div>


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